Adjustable electrical resistance.



l J. A AMMJ PATBNTED MAR.24,1908.

P. 0'. BALL.

ADJUSTABLE ELECTRICAL RESISTANCE.

APPLICATION TILED NOV. 31. 1907.

2 SHEETS-SHEET l.

(Emma/tor @Howcid Dfnftsin PATENTED MAR. 24, 1908.

J F. 0. BALL. ADJUSTABLE ELECTRICAL RESISTANCE.

APPLICATION TILED NOV. 21. 1907.

2 SHEETS-SHEET 2.

crimino- STATES FREDERICK 0. BALL, OF PLAINFIELD, NEW JERSEY.

ADJUSTABLE ELE CTRICAL RE SISTANCE Specification of Letters Patent.

Patented March 24, 1908.

Application filed November 21, 1907. Serial No. 403,109.

To all whom it may concern:

Be it known that I, FREDERICK 0. BALL, a. citizen of the United States, residing at Plainfield, in the county of Somerset and State of New Jersey, have invented new and useful Improvements in Adjustable Electrical Resistances, of which the following is a specification.

This invention relates to adjustable electrical resistance, and consists in certain improvements in the construction thereof as will be hereinafter described and pointed out in the claims.

The purpose of this improvement is to form devices of the character in which the resistance may be readily varied, and consists in mechanisms whereby the lengths of the loops composing the resistance may be quickly and easily varied for this purpose.

The invention is illustrated in the accompanying drawings as follows:

Figure 1 shows a plan view of the resistance with a double series of loops. Fig. 2 a side elevation of the resistance. Fig. 3 an end view of the resistance. Fig. 4 shows a construction in which there is but a single series of loops. Fig. 5 a side elevation of the resistance. Fig. 6 an end view of the resistance.

1 marks the base which is of insulating material, and secured in any place desired by. the screws 2. A series of clampin blocks 3 are arranged upon the base and w ile adj acent to'each other are insulated from each other. Immediately above the block 3 are the intermediate blocks 4, and above these are the blocks 5. These blocks have the grooves fioppositely arranged in them. The terminals 7 are secured in the grooves 6 in the outer sides; one side of each loop being in one block, and the opposite side in the clamp of the adjacent'block so the current travels from block to block through the loops. Clam ing bolts 9 extend through the base and t l irough the blocks 3, 4 and 5, and the thumb nuts 10 are screwed onto these bolts so as to set the clamps formed with the blocks.

It will be readily seen that by loosening the thumb nuts 10, the clamps formed by the blocks are loosened, and loops 10 may be pushed in or pulled out so as to shorten or lengthen the loops as desired, and in this manner the resistance increased or diminished.

The number of intermediate blocks may be varied to suit the capacity required. In the alternative construction shown in Figs. 4, 5 and there-is but a single series. A single series might be used in all cases, but this would require different sizes of parts. By increasing or diminishing the number of with same sizes of parts.

What I claim as new is:

1. The combination of the insulating base; a series of clamps upon the base insulated from each other; and a loop secured by them, the sides of the loop being adjustable in the clamps to vary the length of the loop.

2. The combination of the insulating base; a series of clamps upon the base insulated from each other; and a series of loops arranged in said clamps, one side of each loop being secured by one clamp, and the opposite side of the loop by another clamp to carry the current from clamp to clamp, said loops being adapted to be adjusted as to length in the clamps.

3. The combination of the insulating base; a series of loops and a series of clamps, and each clamp being adapted to secure one side of a loop at the one side of the clamp, one side of another loop at the opposite side of the clamp; and clamping bolts extending through the clamps between the parts'of the loops secured, said loops being adapted to be adjusted as to length in said clamps.

4. The combination of the insulating base; clamping blocks 3, 4 and 5 arranged on the base and adapted to secure a plurality of loops with one side of each loop in one clamp, and the opposite side of the loop in another clamp; and a plurality of loops each having one side secured by one clamp, and the opposite side by another clamp.

5. The combination of the base 1; the clamps composed of blocks 3, 4 and 5; clamping bolts extending through the blocks; and a double series of loops one between the bloli s 3aiid'4; and another series between the blocks 4 and 5, said loops being adjustable as to length in said clamps.

6. The combinationol' the base 1; a series loops in parallel the capacity may be varied of clamps comprising the blocks 3, and 5 a testi nony vvhereof I have hereunto set" having the opposing grooves 6 therem; and 3 my hand 1n the presence of two subscribing the olamplng bolts 9 extending between the Witnesses.

grooves, the loops 8 arranged in the grooves FREDERICK 0. BALL 5 and adjustable as to length; and the terrm- Wltnesses't nals 7 secured in the grooves at the outslde of v RALPH H COLLINS,

the end clamps. CARLOS C. GALLUP. 

